| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for detecting malfunction of programmable control ler which can restart automatically after a temporary suspension of system operation even if malfunction of a memory occurs. SOLUTION: A circuit 13 for detecting malfunction of the memory outputs signal 15 for detecting malfunction of the memory to an NMI detection circuit 17 and a timer circuit 23 respectively when the malfunction of the memory is detected. The NMI detection circuit 17 which inputs the signal 15 for detecting malfunction of the memory outputs an NMI signal 19 to a CPU 21 which suspends after executing processing of the NMI, while the timer circuit 23 which inputs the signal 15 for detecting malfunction of the memory starts timer operation and outputs a reset signal 25 reacting to malfunction of the memory in a reset circuit 27 when data of the timer reaches a fixed value. The reset circuit 27 outputs a system reset signal 29 to the suspending CPU 21 to restart it after the temporary suspension.
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